Geo-location data play an important role in maintaining and/or optimizing modern cellular networks. For example, it may be useful for wireless network operators to understand the geographic distribution of mobile devices and respectively assess geographic distribution of a quality of network service. Geo-location data can be used for identifying locations with a high rate of dropped calls, poor coverage, interference from a neighbouring cell, etc.
Problems of using geo-location data for maintaining and/or optimizing a cellular network have been recognized in the conventional art and various techniques have been developed to provide solutions. For example:
U.S. Pat. No. 7,206,573 discloses a method and system for automatically providing, to a network entity in a wireless network, a call-drop location. The mobile station or base station may determine that a call, in which the mobile station was engaged, has been dropped. In response to determining that a call has been dropped, the mobile station or base station may obtain the location of the mobile station. The call-drop location can be used to identify those areas of the wireless network needing improved radio coverage.
US Patent Application No. 2007/0129086 discloses a method and apparatus for identifying a geographic area having undesirable wireless service. The method includes collecting Radio frequency (RF) environment information of the wireless service, determining locations of a plurality of subscriber units based on the RF environment information, and processing the RF environment information and the locations of the plurality of subscriber units to identify the geographic area having the undesirable wireless service.
US Patent Application No. 2013/0157688 discloses a system for maintaining or optimizing a mobile phone network. The system comprises a plurality of data feeds including at least one radio access network (RAN) data feed to receive RAN performance data relating to performance of a radio access network of a mobile phone network over a period of time, wherein RAN performance data is associated with RAN performance geo-location data. The plurality of data feeds further includes at least one subscriber account data feed including subscriber account geo-location data defining physical locations of subscriber accounts within region of coverage of RAN. The system further comprises a spatial data integration system coupled to data feeds and configured to combine RAN performance data, RAN performance geo-location data, subscriber account data, and subscriber account geo-location data into an integrated spatial data structure, wherein integrated spatial data structure is indexed by at least a spatial element identifier and an attribute identifier.
Geo-location data are indicative of the real-world geographical location of mobile devices. Geo-location of mobile devices can be performed in several ways. For example:
US Patent Application No. 2007/117572 discloses a method for locating and tracking devices in a mobile telephone network comprising the steps of (a) receiving mobile telephone control parameters in a subscriber database; and (b) using one or more location parameter databases (LPDBs), each mapping control parameters to a geographic location and returning a location result when queried. One or more filters are applied to the control parameters that are received by the subscriber database, each filter selectively initiating processing using a LPDB appropriate to the task of the filter and to the current state of the device.
US Patent Application No. 2009/011779 discloses a method and system for calculating the location of a mobile radio terminal in a radio communications network. The method provides for the collection of measurements of radio signal parameters at the mobile radio terminal which are then processed and transmitted to a network processor for calculating the location of the mobile radio terminal. The collected measurements may be filtered and subsets of the measurements may also be selected according to their suitability for particular applications.
US Patent Application No. 2012/0213105 discloses positioning functionality in a wireless communications network in a multi-carrier system. The network node enables UTDOA (Uplink Time Difference of Arrival) positioning measurements for a wireless device in the multi-carrier system. The network node is configured to receive interference or load related information for carriers available for UTDOA positioning measurements and to select at least one carrier for UTDOA positioning measurements based on the interference or load related information.
US Patent Application No. 2012/0258729 discloses estimating position of a mobile device served in a cell of a serving node of a wireless communication network by estimating an angle-of-arrival (AoA) between the mobile device and the serving node based on a precoding matrix indicator (PMI) determined for the serving node in a downlink direction or for the mobile device in an uplink direction. Also estimated is the AoA between the mobile device and a non-serving neighbour node of the wireless communication network based on a PMI determined for the neighbour node in the downlink direction or for the mobile device in the uplink direction. The downlink and/or uplink AoA estimation can be further enhanced by employing interference cancellation in the mobile device and in the radio node, respectively. The position of the mobile device is estimated based on the estimated AoAs.
US Patent Application No. 2012/0264447 discloses a technique for tracking a wireless device. Upon receiving signal strength data for each of a plurality of access points, the signal strength data from the plurality of access points is compared to identify an anchor access point having a highest signal strength. Remaining signal strength data from the plurality of access points are compared to a threshold signal strength to identify at least one attractor access point. A memory is accessed for locations of the anchor access point and the at least one attractor access point. A pull point is calculated along a line from the anchor access point to the at least one attractor access point. A location of the wireless device is estimated as an average of the pull point and the location of the anchor access point.
US Patent Application No. 2013/0122855 discloses a geo-location data acquisition system and method for acquiring communication session data from a mobile radio communications network. A data extraction module extracts call session data continuously from a network of call processors, each call processor supporting mobile communication units in an associated geographical region of the coverage area of the mobile radio communications network. The data extraction module provides the extracted data to one of several storage areas. In each storage area, a record is created of the communication session data for each call made within the coverage area of an associated set of call processors. The records stored in each storage area comprise the data available for all communication sessions in the geographical region associated with the corresponding set of call processors.
U.S. Pat. No. 8,165,599 discloses estimating a location of a mobile station based on wireless communications between the mobile station and a wireless telecommunications network. Call measurement data is obtained for a call involving the mobile station and a plurality of base station antennas. The call measurement data includes round-trip delay (RTD) measurements and received signal strength (RSS) measurements. Expected signal strength is calculated for each significant base station antenna involved in the call, according to a wireless propagation model that accounts for terrain around the base station antennas. For each significant base station antenna, the corresponding expected signal strength, RTD measurement, and RSS measurement are used to calculate an adjusted RTD value. The one or more adjusted RTD values calculated for the one or more significant base station antennas are used to estimate the mobile station's location.
GB Patent Application No. 2352134 discloses a method of locating a mobile telephone handset. The method comprises the steps of (i) calculating a predicted signal property such as signal strength or observed time difference for a plurality of possible locations for the handset, (ii) comparing the predicted signal property with a measured signal property and (iii) deriving from the comparison a probability that the handset is at one or more of the locations. The method can be refined by combining the thus derived probability map with a probability map based on geographical information, or historical data, or both. Thus a peak probability which moves along a path parallel to a road indicates the handset is on that road. Several probability maps, for example based on time differences, signal strength, geographical data and historical data, can be combined simultaneously or sequentially to identify a peak probability.
The references above teach many principles of geo-locating and using thereof that are applicable to the presently disclosed subject matter. Therefore the full contents of these publications are incorporated by reference herein for teachings, where appropriate, of additional or alternative details, features and/or technical background.